Pressure-gauge mechanism



' c. H. GR'AESSER PRESSURE GAUGE MECHANISM Filed May 5, 1921 2 Sheets-Sheet. 1

1% 3 van Carl H M8636 HM, e/ MA?M July 17, 1923. 1.461.730

C. H. GRAESSER PRES SURE GAUGE ME'CHANI SM Filed May 5, 1921 2 Sheets*Shee t 2 HIM Warnegd Patented July 17, 1923.

1,41,73 FEE.

CARL 5H. eaanssnn, or nnrnenronr, CONNECTICUT, ASSIGNOR 'IO MANNING, MAX- WELL & noonnfrNu, on

NEW YORK, N. 'Y., A. CORPORATION OF NEW JERSEY.

PRESSURE-GAUGE MECHANISM.

Application filed May 5,

T 0 all whom it may concern? Be it known that I, CARL H. GRAESSER, citizen of the United States of America, and resident of Bridgeport, in the county of F airfield and State of Connecticut, have in vented new and useful Improvements in Pressure-Gauge Mechanism, of which the following is a specification. 1

This invention relates to pressure gauges and the like and more particularly to improved means useful in connection with the transportation of such gauges .forguarding them against the injurious effects of accidental shocks or blows. i

Pressure gauges of the usual type comprise a Bourdon tube, an index needle, and mechanism intermediate dle for multiplying and transmitting the movements of the former to. the latter. The Bourdon tub'ecommonly consists of a flattened metallic tube bent into the arc of a circle, having one end fixed and communicating with the pressure pipe, and having its free extremity closed andconnected by means of mission mechanism. After the assembling of the gauge, itis carefullyadjusted and tested for accuracy, the index needle usually being so positioned as to rest against a fixed stop pin when in initial or zero position. Bv reason, however, of the supporting of the Bourdon tube at onehend only, it is found to be extremely susceptible to the effects of blows or shocks, and the safe transportation of gauges employing such pressure tubes is an exceedingly diflicult problem. This difficulty is particularly pronounced in connection withjlow pressure gauges,-such for example as. are used in socalled vapor heating systems and the like and wherein theBourdon tube must necessarily be of very thin material.v While elaborate andcostlv attempts have been made to minimize the effects of blOWSIG".

ceived during transportation, and while to a certain extent such injurious effects have been lessened, it is found that no matter how carefully the manufacturermay pack the gauge for transportation, and regardless of what precautions are observed in the selection of the mode of transportation, a large proportion of gauges arrive at their points of destination with the needle standing at a considerable distance from the stop pin. This condition necessitatesthe readsuch tube and neer provide means, by

a link or otherwise to the trans- 1921. Serial No. 466,952.

justment of the gauge which is a delicate operation, requiring care and skill, and in many instances the purchaser of the gauge, without realizing the true facts of the situation, accuses the manufacturer of careless; ness in initially adjusting the instrument, or of failure to observe the proper care in shipping, and demands that the manufacturer replace or repair the defective gauge at his own expense. This condition. of affairs is annoying to manufacturer and con; sumer, and frequently results in loss of business ,to the manufacturer, even though the latter be using the utmost care and employing expensive forms of packing to insure the safety of his product in transportation.

The principal object of the present invention is to overcome the above difliculties incident to the transportation of instruments of the character referred to, and to th employment of which, the safe arrival of the finished and adjusted gauge at its point of sonably be assured.

As the result of elaborate and carefully conducted tests, it has been ascertained that when the gauge is subjected to shocks or blows, the Bourdon tube, which is relatively thin and resilient, is set into vibration, the plane ofvibration varying with the direction of the blow, and the amplitude of its vibration at any point of course varying with the distance of such point from the fixed end of thetube, but beingof appreciable amount even atpointsclosely adjacent such end. At its free end the amplitude of vibration of the tube may be very large and the momentum of the connected parts suflicient to produce a permanent deformation or bending of. the tube or of such parts, with the index needle.

While it has been proposed to provide temporary holding or clamping means for preventing movement of the gauge parts during transportation, such means have proven unsatisfactory from a practical standpoint due to the failure of the user to remove such devices in putting the gauge into use, or by reason of carelessness in removing such devices with attendant injury to the gauge mechanism proper. It has been found, moreover, that if it be attempted to limit the vibrational movement of the tube, as for example by the provision of a fixed destination may rearesultant incorrect setting of Such mchanism commorny the gauge is subjected to stop or stops at intermediate points in its length, the other portions of the tube are affected by shocks to nearly the same extent as before, the fixed stops merely acting as node points in the vibrating tube, if the blow comes in a direction transverse to that portion of the tube with which the stopimeans engage, and permitting the tube to slip by the stop device and take up its full vibration ifthe blow comes from a direction at right angles thereto. As it is obviously impossible to provide stops at all points in the tube, which would render it useless to perform its intended function, it is clear that such mode of controlling the vibration of the parts is not feasible. Such fixed stops moreover, are

found to indent the relatively thin walled tube when the gauge is subjected. to a heavy blow, thus impairing the accuracy of the tube and seriouslywealrening it. Thus the control of the vibrational movement of the tube becomes a" difficult matter from a practical standpoint, and in carrying out the above object ithas been found advisable to abandon the attempt at direct control of the Bourdon tubeand to provide means associated. with the movement transmitting mechanism for securing the desired result. comprises a lever member mounted to turn upon a staff and providedwith a gear sector at one of its ends and having connections at its opposite end with the free extremity of theBourdon tube. For the purpose of the present inven tion,.fiXed stop means may be provided for limiting the oscillation of such lever .in

either direction, the stop means being so positioned that the index needle cannot move beyonddthe limits of the dial scale. With such an arrangement it is found that the vibration of the partsis so damped, and the amplitude of movement thereof is so limited that, while free to perform its proper function, the tube is restrained against excessive movement such as might cause its permanent deformation.

i In gauges of this character, as above stated it is common to employ a lever member as an element mechanism between the Bourdontube and the index. This lever is generally provided at one end with a slidable extension piece which is useful in the initial or subsequent adjustments of the gauge. This extension is formed with a longitudinal slot and is secured in adjusted position by means of set screw passing through the slot and entering an opening in the main portion of the lever. As the extension slide is mounted upon the short arm of the lever, any inaccuracies in setting of the same are greatly amplified at the index needle, and it is of primeimportance, both that the slide be set properly, and-that it maintain its position even when blows or vibration.

of the connecting openings of the extension slide and to this end the may be provided with a fillet beneath its head,

set screw therefor bevelled shoulder or Y such shoulder acting automatically to center the slide relatively to the axis of the screw, and by biting into the edges of the slotin the slide, such fillet may serve in an effectual manner to prevent subsequent movement of the slide even though the screw becomes somewhat loosened.

Preferred means for carrying the above invention'int 'effect is illustrated inthe accompanying drawings in which,

Fig. l is a front elevation of a gauge showing the dial and index needle as removed in order more clearly to illustrate the interior mechanism;

Fig. 2 is a fragmentary vertical section takenon the line (lb of Fig. 1-;

3 is a fragmentary horizontal section on the line 6-CZ of Fig. 2; Figs. a and 5 area plan and elevationcr'espectively of the movement of a gauge mechanism, illustrating the application of a modification of the present invention,"

Figs. 6 and 7 are a plan and side eleva tion respectively of a o-auge movement illustrating a further modification;

Figs. 8 and 9 are a plan and side elevation enlarged scale.

, Referring to Figs. 1, 2, 3, 10 and 11, the usual gauge casing is indicated at 1, such easing having supported therein a bracketZ provided with an outwardly projecting screw threaded nipple whereby the gauge may be mounted'upon a pressureplpe.

Outstanding from one side ofthebracket 2 is an arm duwhich serves to support one end of a pressure tube 5 ofthe Bourdontype; At 6 is indicated the top plate of a movement supporting frame,such plate being secured by means of screws. 7 to the bracket 2. Spaced below the plate 6' is a second plate 8, such plates being held in proper relative'position by means of posts 9, 10;, respectively. The plates 6 and S'are providedwith aligned v wherein is journaled an index staff 11 provided with a hair spring- '12. Aligned openings are; also provided in the plates 6 and 8 wherein is journaled a stall 13 upon whichis'secured a lever member 14.

This lever member is provided at one end an extension member or slide16, to the outer takes over the staff 13, such staff serving as a guide for the slide member. An adjusting screw 21 passes through the slot 20 and has threaded engagement at 22 with an opening in the mainportionof the lever 14, This screw is, preferably provided immediately be neath itshead with'a conical or beveled surface 23, which, when the'screw is set up tightly, engages the of the slot 20 as indicated at 24, in Fig. 11. T his arrangement not only serves to centerthe slot relatively to the axis of the screw but, if suflicient force be applied, the conical portion of the screw is forced into the material of the edges of the slot, thus forming a seat for the screw which prevents substantial movement of the slide even though thescrew becomes somewhat loosened.

As indicated inFig. 3, the bottom plate 8 is provided with apair of screws 25, 26, which engage eyes 27, 28, respectively, formed upon the ends of the arm members 29, 30. These arms project opposite lat eral directions from the plate and are provided with upwardlyexten din members 31.

32, respectively. The members 31, 32 extend transversely of the plane of movement of the sector 15, andare so positioned as to; contact with the edges of such sector whereby to limit the movement of thelatter in both directions. By securing the arms 29, 30 by means of theeyes and screws, it is readily possible to adjust such arms relatively, one to the other, and to the plate8 whereby to vary the limits of movement of the sector 15.

In the arrangement shown in Figs. 4 and 5, the movement frame is indicated as comprising atop plate 6 and bottom-plate 8 spaced apart by means of posts 9" and 10. The index stall is shown at 11 having the pinion 111 and the hair spring 12. The lever stall is indicated at 13 having the lever 1 1 mounted thereon, such lever being pro vided with the sector 15 engaging the pin ion 111. The lever is also furnished with an extension slide 16 secured in position by means of a set screw of ordinary form, or of the type hereinbe'fore described and illus trated in Figs. 10 and 11. In accordance with this modification, the post 10 is pro vided with a transverse opening at 30 through which extends a pin having the oppositely extending portions 31, These portions provide surfaces 33, 34 respectively which lie in the planeof movement of the main lever member 14 or of the extension member 16, and as the elements33, 34 are arranged upon opposite sides of the axis 13. about which the lever turns, the single pin 111g connection with a bracket 18 mounted be varied.

plate;

lever in either direction of movement. By

relativelyjbending the portions31, 32 of the j pin the limits of movement of the lever may In the arrangement"indicated in Figs. 6

and 7 ,1 the top and bottom plates of the move- ,ment supporting frame areindicated at 6 8, respectively. Theseplates are held in l spaced relation byme'ans ofthe posts 9 10 and serve to provide journal bearings tor theindex staff 11 provided with thehair spring .12 and the pinion 111. The plates also have journaled therein the lever staff 13" having mounted thereon the lever 14 provided with the extension 16 and with the segmental portion 15. The segmental portion is provided with a segmental opening lO I and projecting upwardly from the plate 8 is a pin 11 which lies within the opening 40 and transversely of the plane of movement oi the lever. This single pin thus provides for limiting the movement oi the lever in opposite directions. 1

In the arrangement disclosedin Figs. 8 and 9, the top and bottom plates of the move ment frame are indicated at 6, 8, respectively, being spaced apart by means of the posts 9, 10. The index staffis indicated at 11 and the lever staff at 13, s'uchlever staff supporting the lever 14 havingthe extension post 10. as by means of a screw 50 and inl l t th h l l s tcrposerc J6 ween e on or $1101 .Jciew and the upper surface of the plate-6 is a integral arms 52, 53 which are bent downwardly to provide the members 54:, 55 which lie substantially parallel to the axis of the staff 13 and which are arranged for contact respectively with the opposite edges of the lever 14 or of the extension member 16.

'The upper plate 6 is secured to the Extending in opposite directions from the central port-1011 of the plate 51 are The plate 51 with the members 52, 53, 54, x

55 may be formed as a single stamping and mounting uponthe frame. .As the arms 54,

55 may be bent independently onset the lever is limited in-either direction, and as this leverserves to drive the index needle it is clear that the latter is also positively limited in its movement. the lever is connected to the pressure tube bymeans of the link 17 and bracket 18, the tube has a considerable freedom of movement relative to the lever and after the stopping of the lever at either limit of its movement it is still slightextent, the vibration, however, being damped by the connection of the free end of 1 10 bent into suitable form either before or after possible for the pressure tube to vibrate to a j the tube to the lever so that upon stopping ofthe lever engagement with either of the stop elements any substantial and injurious vibration ofthe tube, is prevented.

Thus accidental blowsor shocks to the gauge casingfail to cause permanent injury togthe tube or the gauge movement, or to impress upon suchparts a permanent set such as to require read ustment ofthe lever slide or of the index needle, "The employment of the special form of: adjusting screw also conducesl to permanency or adjustment of the gauge parts in the manner above pointed. out,

and is found to beef particular value in connectionwith a gauge-provided with the stop members above described, aswith such a gauge, the inltlal setting of. the parts is usually sufficient and no further adjustment is necessary.

" Having-thus described the invention in a preferred embodiment of the samevtogether withthemode of functioning thereof, what Iclaim and desire to secure by Letters Pat- 'fixed elements engageable with said lever at opposite sides of itsaxis ,whereby to limit its arcof movement. v V,

3. Agaugehavmg a Bourdontubman 1ndex, and connecting mechanism therebetween, said mechanism comprising a lever member, and a pair of relatively adjustable. and detachable stop members secured to a fixed support and arranged to engage opposite lateral edges of said lever member whereby tovlimit its movement in, either direction.

4. A gauge having a Bourdon tube and a i movement frame coinprlsinga support ng plate, alever member, and apair of stop memberseach having an eye at one of its extrem ities, means engaging the respective eyes for securing said members to the plate, said members being provided with outstanding arms arranged respectlvely for engagement with opposite edges of the lever member whereby to limit the movement of the same in either direction. r

5. A gauge mechanismcomprising a lever and an adjustable extension slide therefor having a parallel walled slot therein, and means engageable with the. lever and prQ- vided with an element constructed and, arranged to bite into the edges of said'slot whereby to retain said slide firmly, in ad'- justed position '6. A gauge mechanism. having a lever, an

extension slide for said, lever, saidjslide having a longitudinally extending, parallel walled slot therein, anda set screw engagmg the slot in said slide and havingthreaded engagement with the lever, said screw, havin a head, and substantially conicalfillet beneath, the head.

Signed by me at Bridgeport, this 2nd day of May, 1921,

, earnn.,enimssnin.v 7

Connecticut 

